Many arrangements for coating small metal components have already been described, as shown for instance in the article by E. Fitzer, W. Fritz and D. Kehr, "Struktur und Eigenschaften von CVD-Schichten" in the periodical VDI-Zeitschr. 114 (1972) no. 16, Nov., p. 1221 onwards. With the methods and apparatus illustrated there, local temperature differences often arise in a component substrate, and, in addition, turbulence can build up between the gaseous reagents employed, so that the rates of chemical separation and deposition are not uniform. Consequently, the coatings produced in any given instance can become very uneven, and some zones on the components undergoing a given coating operation can remain totally exposed (uncoated), such as areas on holders, or on the backs of components, or the like.
For coating small components, use has been made, for example, of rotary reaction vessels heated exteriorly in which chemical separation results in deposits predominantly on the inside walls of the reaction vessel, such deposits being transferred to the components partly by friction. However, in such a coating system, the adhesive bond between a resulting coating and an individual small component is impaired.